1) To assemble and follow a cohort of sisters of women who have had breast cancer.2) To identify genetic and environmental risk factors for breast cancer in a cohort of highly motivated women who are at increased risk.3) To identify genetic and environmental risk factors for other diseases in women.4) To identify affected sister pairs for studies of gene identification and association.5) To compare affected and unaffected sisters to identify risk factors for breast cancer.Accomplishments:This study is in the early planning stages. Focus groups have been conducted with geographically and ethnically diverse groups of women: African Americans sisters in Baltimore, Lesbian women in Washington DC, Latina sisters in San Francisco, and both sisters and survivors in North Carolina. The study plan has also been presented to several advocacy and special interest groups to assess interest and concerns. These groups and meetings have provided insights that will shape the ultimate design of the study. Currently, issues related to confidentiality and use of the Internet for data collection are being explored. Pilot tests will begin shortly. These will be designed to test specific recruitment and data collection strategies and to evaluate the expected sample sizes for specific substudies of interest. Data collection forms are being developed.